Method Init

source/opt/loop_unroller.cpp:348–372

}

void LoopUnrollerUtilsImpl::Init(Loop* loop) {
  loop_condition_block_ = loop->FindConditionBlock();

  // When we reinit the second loop during PartiallyUnrollResidualFactor we need
  // to use the cached value from the duplicate step as the dominator tree
  // basded solution, loop->FindConditionBlock, requires all the nodes to be
  // connected up with the correct branches. They won't be at this point.
  if (!loop_condition_block_) {
    loop_condition_block_ = state_.new_condition_block;
  }
  assert(loop_condition_block_);

  loop_induction_variable_ = loop->FindConditionVariable(loop_condition_block_);
  assert(loop_induction_variable_);

  bool found = loop->FindNumberOfIterations(
      loop_induction_variable_, &*loop_condition_block_->ctail(),
      &number_of_loop_iterations_, &loop_step_value_, &loop_init_value_);
  (void)found;  // To silence unused variable warning on release builds.
  assert(found);

  // Blocks are stored in an unordered set of ids in the loop class, we need to
  // create the dominator ordered list.
  ComputeLoopOrderedBlocks(loop);
}

// This function is used to partially unroll the loop when the factor provided
// would normally lead to an illegal optimization. Instead of just unrolling the